0,2

Sum[d|(2n+1), phi(d)*2^{(2n+1)/d} ] / (4n+2).

Cf. A000013, A000016, A000116.

Bisection of A053634 and A053656.

Sequence in context: A148115 A148116 A149833 this_sequence A149834 A149835 A149836

Adjacent sequences: A026116 A026117 A026118 this_sequence A026120 A026121 A026122

nonn

N. J. A. Sloane (njas(AT)research.att.com), Apr 12 2000